Dragon Ball Z Kai is a complete reworking and remastering of the Dragon Ball Z anime series to more closely fit Akira Toriyama's original story. Padding and filler content has been removed, massively reducing the amount of episodes. Kai was made to commemorate Dragon Ball's 20th anniversary.

Remastering

Vegeta recolored in Kai!

The original Dragon Ball Z series was infamous for being filled with episode-long power up sequences and a great deal of filler. The main reason for this was that Toei Animation was creating the anime concurrently with the manga and would often catch up to Akira Toriyama. Since there was no way to overtake the manga, the series would extend certain scenes a great deal, or just add filler scenes, such as the infamous driving school episodes. The filler bumped up the series to a paltry 291 episodes, that was released in Japan, fully remastered frame by frame, in a box set known as the Dragonbox. This series was later released in North America as well in its entirety.

Toei Animation then announced that they would be remastering the series once more for high definition. What this entailed was going through the original film prints and cleaning up any dirt or scratches that had accumulated over time as well as fully redrawing some scenes. Other scenes were recolored to become more consistent with the series later on. For example in the first couple of episodes Piccolo's blood was red, where as it was later established that Namekian blood was purple. Another example of this is the awkward coloring of Vegeta prior to his first landing on earth. The biggest difference however was that Kai was to be cut down from 291 episodes to around 100, thus eliminating the extended power up sequences and filler episodes.

Goku censorship!

The series received some flak however, when Toei not only cut out filler scenes, but also some scenes that were canonical and in the original manga. The blood and violence was also toned down a noticeable amount. An example of this is when Piccolo shoots a beam through Goku and his brother Raditz, the hole is no longer shown as the beam passes through but instead it more closely resembles a bruise. Certain scenes received other forms of censorship, notably, Goku as an infant was censored so that his private area was no longer visible.

Not only was the video remastered, but so was the audio. The majority of the voice actors returned to reprise their roles, so mistakes with the dialogue were also corrected. An example of this would be during the Vegeta saga, Gohan yelled Kamehameha, when his hand was in fact in the Masenko attack position. The music was also re-scored by composer Kenji Yamamoto.

Aspect Ratio Confusion

The correct aspect ratio for Dragon Ball Z Kai is 4:3.

When the Kai series originally aired on Japanese televisions in was cropped to 16:9 widescreen, which left many wondering why this was done. It was in fact done because widescreen was a requisite for Japanese television stations to air modern anime shows. When the DVDs and Blu-ray discs were released, the DVDs were in the widescreen that aired on television, however the Blu-ray discs contain the original 4:3 version. The Blu-ray discs maintain what Toei considers to be the correct aspect ratio for the series.

North American Release

Nicktoons?!

Not long after it's release in Japan, FUNImation announced that it had picked up the rights to Kai and would be re-dubbing the entire series with a script that more closely resembled the Japanese script. Most voice actors returned and reprised their roles such as Sean Schemmel as Goku (although some voices have changed up). The series was renamed Dragon Ball Z Kai in North America so as to have better brand recognition, and the first DVD and Blu-ray discs were slated for release on May 18th 2010.

Dragon Ball Z Kai began airing on television on the Nicktoons station, and it was also later announced that it would be airing on the CWKIDS station as well.